Emails and similar communications sent by one or more users may follow various patterns. For example, under particular circumstances, a user or group of users may tend to draft and send emails sharing particular attributes. Suppose users within a particular department are required to draft and send reports by a particular deadline. Such outgoing communications likely will conform at least to some extent to one or more patterns. For example, the outgoing communications may share a number of textual segments that may be considered “boilerplate” or “fixed,” while other textual segments may differ between communications and thus may be considered “transient” or “variable.”